Quote:
Originally Posted by Cd
Assuming you are getting around 4 mpg, and If your current Cd is around .75, and you decrease it by 60%, ( to .30 ) you would only boost your mileage by just over one mpg at 50 mph.
At slower speeds, like this vehicle is capable of it would be even less.
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What? Oh wait a sec. 1 mpg is a 25% increase in FE... Even then, I wonder what numbers you are using???
From Unimog links:
Quote:
Width 78.8 inch/6.57'
Height at highest point 105.5
Ground Clearance 17.5 inches/ 105.5-17.5=88 or 7.33'
Weight 7,920
FE 13 mpg
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FA (?) 48.18 sq. ft , EE .19, drive train efficiency .9, #2 diesel
CRR (?) .015
Aerodynamic & rolling resistance, power & MPG calculator - EcoModder.com
Gets 13mpg @~37mph... close to 50:50 aero and rolling resistance.
I got 9.36 mpg at 50mph with .75 Cd and a 66:34 aero to rr (respective)ratio. At .30 Cd I got 15.5 mpg, a
65% improvement in mpg and a 44:56 aero to rr ratio.
I stand by the fact that aero improvements are almost always beneficial. Would adding another axle to this vehicle cut rolling resistance by a lot?